export default (function(Prism) {
  Prism.languages.sass = Prism.languages.extend('css', {
    // Sass comments don't need to be closed, only indented
    'comment': {
      pattern: /^([ \t]*)\/[\/*].*(?:(?:\r?\n|\r)\1[ \t]+.+)*/m,
      lookbehind: true
    }
  });

  Prism.languages.insertBefore('sass', 'atrule', {
    // We want to consume the whole line
    'atrule-line': {
      // Includes support for = and + shortcuts
      pattern: /^(?:[ \t]*)[@+=].+/m,
      inside: {
        'atrule': /(?:@[\w-]+|[+=])/m
      }
    }
  });
  delete Prism.languages.sass.atrule;


  var variable = /((\$[-_\w]+)|(#\{\$[-_\w]+\}))/i;
  var operator = [
    /[+*\/%]|[=!]=|<=?|>=?|\b(?:and|or|not)\b/,
    {
      pattern: /(\s+)-(?=\s)/,
      lookbehind: true
    }
  ];

  Prism.languages.insertBefore('sass', 'property', {
    // We want to consume the whole line
    'variable-line': {
      pattern: /^[ \t]*\$.+/m,
      inside: {
        'punctuation': /:/,
        'variable': variable,
        'operator': operator
      }
    },
    // We want to consume the whole line
    'property-line': {
      pattern: /^[ \t]*(?:[^:\s]+ *:.*|:[^:\s]+.*)/m,
      inside: {
        'property': [
          /[^:\s]+(?=\s*:)/,
          {
            pattern: /(:)[^:\s]+/,
            lookbehind: true
          }
        ],
        'punctuation': /:/,
        'variable': variable,
        'operator': operator,
        'important': Prism.languages.sass.important
      }
    }
  });
  delete Prism.languages.sass.property;
  delete Prism.languages.sass.important;

  // Now that whole lines for other patterns are consumed,
  // what's left should be selectors
  delete Prism.languages.sass.selector;
  Prism.languages.insertBefore('sass', 'punctuation', {
    'selector': {
      pattern: /([ \t]*)\S(?:,?[^,\r\n]+)*(?:,(?:\r?\n|\r)\1[ \t]+\S(?:,?[^,\r\n]+)*)*/,
      lookbehind: true
    }
  });

});
